System for measuring the capacity of electrical conductors.



FIGURE 1 4 0. M. LEIGH w. E. HAGUE. SYSTEM FOR MEASURING THE CAPACITY OF ELECTRICAL GONDUGTOES.

I APPLICATION FILED JULY 16, 1907. I I

Patented Aug. 13, 1912.

3 SHEETS-SHEET l.

' WITNESSES- INV TURS 1 BYTHEIRYATIZY.

0; M. LEIGH & G. E. HAGUE.

' SYSTEM FOR MEASURING THE CAPACITY OF ELECTRICAL GONDUGTORSK APPLICATION FILED JULY 16, 1907. I 1 35,204, Patented Aug. 13,1912.

3 SHEETSSHEET 2.

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L I w B rrNEssE-s INVENTDRS.

s a I I u BY THEIR ATFY. -6,

0. M; LEIGH & G. E, HAGUE. SYSTEM FOR MEASURING THE GAPAGITY 0F ELEGTRIQAL GOND'UGTORS.

I APPLICATION FILED JULY 16', 1907. I

' Patented Aug. 13, 1,912.

' Q 3 SHEETBSHEBT 3.

InvenIuI's Elsua-rM'Jiemh umTEn STATES oscim m. LEIGH AND enemies E.H'AGUE;

- s'rnomnnns-canrson 'rnrnrnonn MANUFACTURING comma, or noorrns'rnn;

PATENT onricn.

053 noonns'rnn, n nwaonx, ASSIGNORS 'ro nnw roan, A CORJEOBIATION. or new YORK.

SYSTEM Eon innnsnmm. run oarhorrr or nnnornrenn oonnoerons.

Spetifioation of Application filed. July 5.6,

To ollivkamiitmy concern: I

.-B&: itknown that. we, OSCAR M. LEIOII- an CW8: HAGUE, citizens ot the United States, residing at Rochester, in the county ofi Monroe and State of New York, have invented a new and Impndved System for Measuring the Capacity of Electrical Conductors, of which 'thefollowing .isa specification.

In measuring the capacity; of electrical conductors, it. has been: the usual practice in the past to connect such conductors to a suitable charging source of electric energy l --for a certain time interval, to; then discomneat such conductors from such charging source and immediately after such disconduetors relatively to such condenser. In op crating such a system as just indicated, it has been the usual practice to make useof a manually operated key for: directly connecting such charging source of energy to the-conductors tobe tested, and to subsequently connect these conductors by means .of the same key to the galvanometer. for measuring the charge. Inasmuch as the quantityof electrification imparted tothe conductors for any given potential of the charging source depends, below. the fuliycharged condition, upon the length of time that such conductors are connected to such source, it is apparent that in systems of this character it is very desirable to provide means for accurately timing the intervals of charging so that when it is desirable to make several successive tests under the sameconditions, as for instance in testing telephone cable, these time intervals shall be exactly alike. For

economical considerations in operating such testing systems .it is 31180 desirable that the discharge interval-s through the galvanometer shall be of'no. longer duration than is Letters-Patent.

1907. Seria1No..38fl,09L."

' tions' of such galvanometer.. Since the charging is usually done by a batteryof j high potential,: a comparatively short time I interval is suihcient for the charging inter- .val, while a, comparatively long. interval of effected only by the electrification stored up in the associated conductors during the charging interval. In forme r systems of testing. in which theseintervals have been determined entirely by a manually operated key, the accuracy of the measurements has operator to establish the charging and discharging mter'yals successively in exactly. the same manner..

the capacity of conductorsautomatically, that is, to connect such conductors to acharging source of ele trio energy, to. maintain; such charging co ition for a. certain predecharging condition and immediately establish a discharging condition through a suit- (able measuring instrument, usually a galresistance about its terminals and to main.-

all of the apparatus to its normal condition. All of this weaccomplish automatically, that is, by the single clos'ure ofa key and by our given adjustment of the apparatus, remain fixed for successive measurements and therefore all error due to differences in the lengths of these intervals is eliminated. It is also an object of our invention to. se-

cure relatively longer intervals of discharge than charge, by effectinga much slower rate of deenergization than energization of the electro-magnetic mechanism involved in determining the length of such charging intervals by i'ts-energization and this slower deenergization we-secure by closing a low resistance path on paths between the terminals of an energizing winding or windings of such electrosmagneticmechanism. It is also an object of our ventionto maintain the same intervals of charging necessary for accurately reading the deflecapparatus independently of the length of time the key is held in its operative position,

discharge 18 required since] the discharge is.

tel-mined interval and then to interrupt such -van meter and associated; adjustable shunt,

ta/inthis discharging condition for a certain predetermined interval and to then restore v Patented Aug. 13,

dependedentirely upon the ability: of the.

V It isan ob ect of our inventidn to measure invention we establish intervals of charging and discharging which for any .105 and discharging-for any arrangement of the It is also an object of our invention to,se--

cure all of the above results with a minimum amount of apparatus involved.

The several drawings illustrating our invention'are as follows:

Figure l Isa diagrammatic view of all of the apparatus and circuit connections used in our system, while Figs. 2, 3 and 4 show modified arrangements of apparatus and circuits by which difi'erent'char ing inter gimilar letters refer to similar parts throughout the several views.

Re erring to Fig. 1, the several relays 1, 2, 3, 4 and 5 are of ordinary telephonic construction and are connected so that they are suitably operated one from the other and that they also operate other relays 6, 7 and 8 at the proper. time, these latter relays being especially de'- signed to withstand high voltage and pre vent leakage, since they are the relays immediately concerned in connecting the conductors to be tested first to the charging source of current and then to the'galvanometer or' other instrument used for measuring the. charge retained by the conductors tested. The general lan of this system is to first connect the con uctors to be tested, for a certain predetermined time intervalto a source of charging current of constant voltage, such voltage being sufiicient to charge such conductors sufiiciently in a short interval. Next, a shunt circuit of adjustableresistance is closed across the terminals of the galvanometer and at the close of the chargmg interval the charging'circuit is broken and the charged conductors are immedia ely connected to the terminals of the galvanometer. The result of this is that'the charged conductors discharge while thus connectedthrough both .the shunt circuit and the galvanometer coils and a throw of the ga-lvanometer will be produced which will be a measure of the quantityof electrification retained by such conductors, since prior to the tests in any case the constant of the galvanometer is determined experimentally in anyxwell known manner not shown and the resistance of the shunt circuit is adjusted so that.the throw for the conductors to be tested will be the most advantageous for the I Thus by comparing the deflections for any test wit the constant of the galvanometer, .the quantity of electrification of the" conductors is measured, or in other words, .the capacity of the conductors charged is proportional to such quantity of electrification; thus ifthe constant of the alvanometer is' 'cletcrmined by using a 'stan a'rdcondensen'by asirnple",

comparison of the throw of the galvanomw tor for any test with the throw for the stand-' ard condenser, the capacity of the conductors tested may be determined very readily. The relays 1, 2, 3, 4 and 5 are designed to be operated one from another when one of such relays is actuatedb cosing its operating circuit and they e ect the operation of the relays 6, 7 and 8, which in turn cause the charging anddischarging of the conduc tors to be tested in themanner just above described. In the example shown in Fig. 1 a cable C is indicated having one of its con-' iductors 411 connected to wire 68, while'the rest of such conductors w are connected together and to wire 67 and also to the sheath s of the cable which sheath is grounded as indicated at G. The purpose of this con-- nection is to test the capacity of the conducs tor w against all of the other conductors w of the cable. In the example shown, a galva nometer g is used for measuring the capacity.

When the key K is moved to the left, a circuit is closed as follows: grounded terminal of battery B, wire 21, wire 45, key K, contact 46, wire 40, winding of relay 2, wire 41, wire 24, back to battery B. Thus relay 2 is energized and contacts 14 and 15 are closed, establishing the following circuit: grounded terminal of battery B, wire 21, wire 43, contact 20, wire 38, contact 14,

wire 39, winding of relay 8, wire 7 0, back to batteryB. Thus relay 8 is energized and contacts 55 and 56 are closed,:by which the charging battery B is connected through resistance' R to -wires 67 and 68 and thus to the conductors to and w to be tested. This circuit is closed as follows: grounded terminal of battery B wire 65, contact 55, charging lead 66, backf-contact 53,-wire 67, conductors-w, conductor w, wire 68, back contact 51, charging lead 63, contact 56, wire 69, resistance R ,-back to batter B. At

the time of closing contact 15, re ays 4 and 5 are energized as follows: grounded terminal of battery B, wire 21, wire 45, key K, contact 46, wire 37, contact 15, wire 28, contact 1.0, winding of relay 4, wire 30, wire 27, winding of relay 5, wire 24, back to battery B. Thus contacts-9 and llare closed and contact '10 is opened. The 0 ening of contact 10 energizes relay 3 as f0 ows: grounded terminal of battery 13,, wire 21, wire 45, key K, contact 46, wire-37, contact 15,- wire 28, wire 33, winding of relay 3, wire 34,

wire 29, winding of relay 4, -wire 30, wire 27,

21, wire 25, contact 11, wire 26, wire 39,

winding of relay 8, wire 70, wire 24, back to battery B. The closing 05 contact 9 opcrates relay 6. as follows: grounded terminal vanometer the charge from conductors 'w and The connection is as follows: galof battery B, wire 21, contact 9,- wire 22, wire 23, winding of relay 6, wire 61, wire 70, wire 24, back to battery B. Thus relay 6 is energized and connects the galvanometer g with the adjustable resistance R preparatory to sending through such resistance and galvanometer g, wire 59, contact 50, wire 58,

resistance R, wire 57, back to galvanometer g. i The operation of relay 3 closes contacts 12 and 13 which close circuits as follows: grounded terminal ofbattry. B, wire 21, contact 9, wire 22, contact 12, winding of relay 3, wire 34, wire -29,\winding of relay 4, wire 30, wire 27, windin of relay 5, wire 24, back to battery B. T us a locking circuit is established for relays 3, 4 and 5 which is maintained until .one of such re-- lays is de'einergized. The closing of contact 13 energizes relay 1 as follows: groundedterminal of battery B, wire 21, wire 31, contact 13, wire 32, winding-of relay 1, wire 44, 1 wire 24, back to battery B. The operationof relay 1 closes contacts 17 and,-19 and opens contact with the following results:

. The closing of contact 19 operates relay f7 log of relay 4 as follows: grounded terminal of battery B,

wire 21, wire. contact. 19, wire 42, winding 7 of relay 7, wire 64, wire (51, wire 7 0, wire 24, back to battery B. Thus relay 7 is operated, which by breaking contacts 51 and 53 and closing contacts 52 and 54, interrupts the connectionof wires ()8 and 67 through such gizing circuit also above traced through contact 11 of relay 4. The closing of coin tact 1'? short circuits the energizing windas followsz'winding of relay 4. wire 30. wire 27, contact 17, wire 29, backto the winding of relay 4. 'This causes the 'detincrgization of such,v relay and closes contact 10 and opens contact 11. The opening of contact 11 opens the second energizing circuitabove described for relay S and thereby permits the deenergization of such relay and the opening of contacts 55 and 56 with-' out, however, producing any operative change in the circuits, since the circuit controlled by such contacts is at this time opened by the energized condition ofrelay 7 opening contacts 51 and 53. The closing of contact 10 short circuits the energizing winding ofr'elay 3"as follows: winding 0 48, wire 23, winding of relay 6, f '70, wire 24, b ack to battery 'Thus a 130 relay 3, wire 34, wire 29, contact 10, wire 28, wire 33, back to winding of relay 3. This causes the denergization of relay 3 and the opening of contacts lZ-and 13. The opening of contact 12 opens the locking circuit above described for relays 3, 4 and 5 and thus causes the denergization of relay 5 and the opening of contact 9. The opening of contact '13 opens the energizing circuit :above described for relay 1 and thereforecausesthe' denergi'zatipn of suchrelay and the opening of contacts 17 and 19 and the closing of contact 20. The opening of contact 9 opens the energizing circuit above described for relay 6 and thereby de'elnergizes such relay. The opening contact 19 opens -.the energizing-circuit of relay 7 above described and thereby opens contacts 52 and 54 and closes contacts 51 and 53, thereby terminating the-discharge interval and the closing of contact 20 does-not again operate relay 8 since contact 46 has been openedby permitting the key K to resume its normal ,zposition, for which position no contact is made by such key.. The opening of contact- 17 removes the short circuit from r'ellay 4 above described, thereby restoring the circuit of such relay to its normal condition ready for the next operation. It is occasionally desirable to prolong the interval of discharge, which is done by holding the key K to the left thereby closing contact 46 which, as long as it is held in this position, maintains the energizing circuits above described for relays 2 and 5. A locking circuitis provided for relay 1 by means of contact 18 on such relay and contact 16 on relay 2 by which such relay 1 when cperated as above described, closes contact 18 and if relay 2 is maintained operated and contact 16 is therefore closed, the locking circuit is closed as follows: grounded terminal of battery B, wire '21, wire 36, contact l6,wir.e 35, contact 18, wire 32, winding of relay 1, wire 44, wire 24-, back to battery B. Thus as long as the key K is held to the left and contact46 is closed, relay 1 .is energized, thereby maintaining relay 7 energized, for which condition wires 68 and 67: and therefore conductors w and w connected thereto are maintained in connection with the galvanometer g and resistance R. It will be noticed from the circuits above described that-when the relay 7 is not energized if 'the relay 6 is energized, the resistance R and galvan'ometer g are connected in series and the motion of the galvanometer coil is dampened or retarded, which condition may be secured when desired by moving key K to the right thereby closing contact 47 and energizing relay 6 as follows: grounded terminal of battery B, wire 21, Wire 45, key K, contact 47, wire ire 61, wire means is provided for dampening the motion of the galvanometer coil as desired.'

It is to be noted that the interval of charge is determined by the length of time required for the successive energization of relays 4c, 3 and 1, since the energizing circuit of relay 1 is closed at the same instant that the en.-

ergizing circuit of relay 8 is closed, and

that the charging condition is maintained until relay 7 operates, which is the direct result of the operation of'relay 1, which, however, is operated by relay 3 which in turn is operated by relay 4. It will also be noted that the interval of discharge is determined by the length oftime required for the deenergization of relays 1, 3 and 1 and that this is a much longer interval than .that required for their energiaation, since relay-4 is deenergi'zed by havin' an, external path of low resistance c osed be tween its terminals which relay in turn closes an external path of low resistance between the terminals of the winding of relay 3. By this device, therefore, it is possible to secure just the condition desired, that is,

i to establish a longer interval of discharge than of charge by the use of the same mechanism as used in determining the charging interval, and b this device it is also possible to reduce tlie amount of mechanism involved to a minimum for any required dis charge interval.

It is generally found adyisable to use a separate source-of energy for charging the are supposed to have the same conncctions.

extending from them as indicated in F ig. 1, and hence these connections and the apparatus controlled thereby are not shown in Fig.5 for the sake of clearness.

In Fig. 2 a modification of our invention is shown in which the chargin and dis-- charging intervals are shortened -by.omitting one of the operating relays. In thisfigure the circuits controlled by relays 6,

'7 and 8 are not shown since they are identical with those shown in Fig. 1. ,In this modificatlon, operating relays 1, 2, 3 and 5 are employed similarly to the corresponding relays used in the modification shown in Fig. 1, the operation of the relays shown in Fig. 2 being as follows: When the key K is moved to the left closing contact 46 an energizing circuit is closed through the winding of relay 2 as for This closes contacts 14, 15 and 16. and contact 15 in turn' closes a circuit as follows: grounded terminal of battery B, Wire 21, wire 45, key

K, contact 46, wire 37 contact 15, wire 33, winding of relay 3, wire 34%,- wire 27, wind-' ing of relay 5, wire 24, back to battery B. Thus relays 3 and 5 are energized closing contacts 9, ll, 12 and 13. The closin of contact 14 operates relay 8'as describe for Fig. 1. The closing of contact 9 by the operation of relay 5 energizes relay 6 as described for Fig. 1; the closing of contact 12 closes a locking circuit for relays 3 and 5 as described for Fig. 1% for relays 3, 4, and 5; the closing of contact 13 closes the ener- 'gizing circuit of relay 1 as described for Fig. l and thereby closes cont-acts 17, 18 and 19 and opens contact 20. The closing of contact 11 serves the same purpose as described for Fig. 1 for contact 11 on relay 4. Contacts 16, 18, 19 and 20 perform the same function as described for Fig. 1 while contact 17 short circuits the winding of relay 3 as follows: winding of relay 3, Wire 34, wire 27, contact 17,'wire 33, back to winding of relay 3. Thus it will be seen that the closing of contact 46 operates relay 2, which in turn simultaneously op erates relays 3, 5 and 8; also the operation of relays 3 and 5 operates relays 1 and 6 as already described for Fig. 1, and further that the operation of relay 1 operates in the manuer alreadydescribed to end the charging interval-and begin the discharging interval by operating relay 7. From the circuits just traced it is also apparent that the operation of relay 1 deenergizes relay 3, thus dcenergizing relays 1, 5 and 8. The deenergization of relays l and 5 deenergizes the relays 6 and 7 as already described. From this it appears thatthe charging interval extends from the operation of relay 2 until the operation of relay 1; that is, it is measured by the time required for the successive operation of relays 3 and 1 and that the interval of discharge is measured by the time required for relays 3 and 1 to be deenergized and that such interval is relatively longerthan the charging intervaldue to the manner in which relay 3 is deenergized; that is, by short circuiting its terminals instead of open circuiting its energizing circuit.

'In Fig. 3 a modification of our invention is indicated similar to the modification shown in Fig. 2, but with this difference,

that instead of showing anarrangement for securing a shorter interval of charge and discharge, Fig, 3 shows an arrangement for securing longer intervals of charge and discharge than indicated in Fig. 1. In this modification, operating relays l, 2, 3, 3, 4 and 5 are.. eniployed, the circuits being similar to those already described for Figs.

essence 1 and 2. The only di fierence is, the winding of relay- 3? is inserted in the circuit bein 1- and is provided with a normally closedcontact.v 71, which serves to normally short circuit'the energizing winding of re- Pay 3,. the contact 10 of relay 4 normally serving in this modification to short circuit the energizing winding of relay 3 Thus it will-be seen inthis modification, when key K is moved to contact 46, the relay 2 is opera-ted as already described, thereby in turn simultaneously operating relays 4, 5

and 8.. The operation of relays 4 and 5 operates .relays 3 and 6 and the operation of relay 3 operates relay 3 which in turn operates relay 1 by which, as already 'described, relay 7 is operated and relay 4 is denergized. The deenergization of relay 4 causes the de'e nergization of relay 3 by closing an external path of low resistance between the terminals of such relay 3*- resistance between the terminals of the energizing winding of relay 3 through contact 71. Thedeenergizat-ion of relay 3 pro-- duces the same results as already" described for Fig. 1. Thus it will be seen that the charging interval in this modification is measured by the time required for the suc-. cessive energization of relays 4, 3*, 3 and 1,; and that the discharge interval is measured by the time required for the deenergization of relays 4, 3*, 3 and 1, and also that such interval of discharge is relatively longerthan the charging interval, due to the mannor in which relays 3, 3 and 4 are deener efl'ccted; that is, if it is desired to have a comparatively long charging interval without increasing correspondingly the discharging-lnterval, it is only necessary to omit one or more steps in the deenergization.

of the relays of such series; that is, for instance as shown in Fig. 4, the dec'nergization of relay 4 may readily be made to deenergize relay 3'directly as indicated in Fig. 1 by closing an external path of low resistance between the terminals. of the energizing winding of relay 3, although at. the same time the relay 3 shown in Fig. 3 may be a necessary factor in determining the charging interval, that is, the energization of"v relay'B may be made to depend upon the :case as indicated in Fig. 3, tweenthewindings of relays 3 and 4 shown energization of relay 3P in this particular In the arrangement shown in Fig. 4 it is to be observed that the sequence of energization of the several relays 2, 4, 5, 3, 3

and 1 is precisely the same as that already described in connection with Fig. 3, while the result of the-operation 0t relay 1 and the subsequent denergization of relay 4 by the short-circuitingof its: winding through contact 17, closed by the energization of relay 1, not only short circuits the energizing winding of the relay 3*, but also conductors. 75 and 76. That is, the deen- .ergization of relay 4 immediately etfiects the d'energization of relay 3, therebyeliminating the operation of the relay 3 durin the sequence of den'ergization of the severe .relays. through contact 10, and the denergization .of relay 3 closes an external'path of low From the operation of the apparatus shown in Figs. 2, 3 and-4, it is quite apparent that with a given set of testing apparatus constructed in accordance with our invention, in which there IS a serles of relays employed to secure a long interval of charge and discharging of the conductors,

any desired charging and discharging intervals less than the maximum may be secured by properly connecting the relays,

and furthermore that by connections similar ,to those shown in Fig. 4 the length of the charging interval may be changed relatively to the length of the discharging in terval.

l/Ve believe that the automatic testing or measuring of the capacity of associated elec trical conductors has not been accom lished prior to this invention, that is, t at no. mechanism has been employed by means of" which the single closure of an electrical by means of contact 74, closed by the de- I energization of relay 4, the energizing wind- 8'0 mg of relay 3-15 short-crrcuited through the key operates suitable mechanism to charge and discharge electrical conductors for predetermined and ad ustable intervals in such a manner as to measure the capacity of such conductors, and we therefore claim broadly the fundamental teatures of such a system.

We would have it understood that many other modifications maybe used in following out our invention without departing from the spirit thereof, and we do not limit ourselves, therefore, to ,the exact embodiments 0t such invention: indicated in the accompanying drawings andspecification,

hat we claim 1. In a system for measuring electric capacity, an electric conductor, a measuring instrument, a sour'ce of operating current, a source of charging current,'a manually operated switch, mechanism initially oper ated by current from said operating source through contacts of said switch adapted to complete a charging circuit between said instrument, a source. of charging current, a,

manually operated switch, mechanism initiallyoperated by the actuation of said switch to complete a circuit between said source and said conductor and to thereafter interrupt said circuit and complete a circuit between said conductor and said measuring instrument, the time of charge of said COI1- ductor being predetermined and being independent of the manner of operation of said manually operated switch, substantially as described.

3. A system for measuring electric capacity, comprising ameasuring instrument,

an electric conductor, a source of charging current, and instrumentalities for connecting said source with said conductor,' disconnecting it therefrom and connecting said conductor with said measuring instrument, the time during which said source is connected with said conductor being the same for each successive operation and being independent of the manner in which the actuation of said inst-rumentalities is initiated, substantially as described.

4:. In a system for measuring the capacity of associatedrelectrical conductors, electromagnetic mechanism a source of electric energy adapted to operate such mechanism, a key for operating such mechanism, a source of electric energy adapted to charge the conductors to be tested, an instrument adapted to measure electrical capacity, the actuation of such mechanism by such key being adapted to automatically'connect such conductors to such charging source of electric energy for a predetermined interval and then to interrupt such charging circuit and connect such conductors thus charged to such measuring instrument and restore such mechanism to its normal condition and such charging interval being independent of the intervalsuch key is held in its operative position.

5. In a system for measuring the capacity of associated electrical conductors, a pluralityof electro-rnagnetic devices 'a source of electric energy adapted to operate such devices, a key for operating a first of such devices, a source of electric energy adapted to charge the conductors to be tested. an instrument adapted to measure electrical capacity, the operation of such first device being adapted to successively operate others of such devices and the. operation of such devices brings about the connection of the instrument adapted to measure electrical capacity, the operation of such first device being adapted to successively operate others of such devices and the operation of such devices being adapted to connect the conductors to be tested to such charging source of electric energy tor-a predetermined interval, disconnect such conductors from such source of energy, connect such charged conductors to such measuring instrument and then restore the devices thus operated to their normal condition.

7. In a system fpr measuring the capacity of associated electrical conductors, a plurality of elect-ro-magnetic devices a'source of electric ener adapted to o crate such de vices, a key or' operating a rst of such devices, a source of electric energy adapted to charge the conductors to be tested, an in strument adapted to measure electrical capacity, means whereby the oper tion of such first device successively operat is others of such devices, means whereby the operation of such devices connects the conductors to be tested to such charging source of electric energy for a predetermined interval, disconnects such conductors from such source of energy, connects such charged conductors to such measuring instrument and then restores the devices thus operated to their normal condition.

8. In a system for measuring the capacity of associated electrical conductors, a plurality of electro-magnetic devices a source of electric energy adapted to operate such devices, a key for operating a first of such devices, a source of electric energy adapted to charge the conductors to be tested, an instrument adapted to measure electrical capacity, the operation of such first device being adaptedto successively operate others of such devices and the operation of such devices being adapted to connect the con-X ductors to be tested to such charging source of electric energy for a predetermined inter val, disconnect such conductors from such source of energy and then connect such charged conductors to such measuring-instrument, such charging interval being independent of the interval such key is held in its operative position.

9. In a system for measuring the capacity of associated electrical conductors, a plurality of electro-magnetic devices a source instrument adapted to measure electrical capacity, the operation of such first device bemg adapted to successivelyoperate others of such devices and the operation of such devices being adapted to connect the con-' ductors to: be

val, disconnect such conductors from such source of energy, connect such charged con-'- charge the conductors to be tested, an in-- 'strument adapted to measure electrical capacity, the operation of such fir'stdevice belng adapted to energize and deenergize the remaining devices of suchseries such operation serving successively to connect the con- 'ductors to be tested tosuch charging source of electric energy for a predetermined interval, disconnect such conductors from such source of energy and then to connect such conductors to such measuring instrument, such charging and discharging intervals be ing determined respectively by the intervals required for successively energizing and successively de'nergizing such devices.

11. In a system for measuring the capacity of associated electrical conductors,- a series of electro-magnet-ic devices a source of electric energyadapted to operate such de-" vices, a key for-operating a first device of such series, a source of electric energy adapted to charge the conductors to be tested, an instrument adapted to measure electrical capacity, the operation of such first device being adapted to energize and doe-nergize the remaining devices of such series such operation serving to connect the conductors to be tested tosuch charging source of electric energy for a. predetermined interval, disconnect such conductors'from such source of energy and then to lconnect such conductors to such measuring instrument, such charging and discharging intervals being determined respectively by the intervals required for successively energizing and suecessively deenergizing such devices, such deenergization resulting from closing an external electrical path of low resistance between the terminals of an energizing windtested to such charging source of electric energy for a predetermined intercharging interval is relatively greater than the-charging interval.

.12. In a systemfor measuri g the capacity of associated electrical conductors, a series of electro-rnagnetic devicesa source of electric energy adapted to operate such devices, a key for operating a first device of such series, a source of electric energy adapted to charge the-conductors'to be tested, an instrument adapted to measure electrical =capacity, the operation of such first device being adapted toenergize and deenergize the remaining devices of such series such operation serving toconnect the conductors to be tested to such charging'sourc'e of electric energy for a predetermined interval, disconnect such conductors from such source of energy and then to connect such conductors tosuch measuring instrument, such :charging and. discharging intervals being determined respectively-by the intervals required for successively energizing and successively deenergizing such devices, such deenergization resulting 'from closing external electrical paths of low resistance between the terminals of energizing .windings of such devices whereby the discharging interval is relatively greater than the charging interval.

13. In a system for measuring the capacity' ofassociated'electrical conductors, a series of relays a source of electric energy adapted to operate such relays, a key for. operating a first relay of such series, a source of electric energy adapted to: charge the conductors to be tested, an'instrumentadapted to measure electrical capacity, a shunt circuit of adjustable resistance adapted to be closed between the terminals of such instrument, means operated by such first relay for connecting the conductors to be tested to such charging source and for energizing a second of.such relaysmeans'operated by such second relay for c' osing such shunt circuit, means for successively energizing he remaining relays of such series each from the one preceding it, means for maintaining such relays energized until the operation of the last of such relays,- means operated by the last of such relays for disconnecting such conductors from such charging source and for connecting such conductors to such instrument and forat the same time dei nergizing one of, such series of relays, means actuated by the deenergization of such last mentioned relay for deenergizing another of the relays of such series, means for similarly de'e'nergizing the remaining relays of such series, means actuated by the deenergization of the last relays of such series for disconment and for immediately thereafter opening such shunt circuit whereby the apparal tus is restored toits normal condition.

ing of one of such devices whereby the disnecting such conductors from such instru- 0nd of such relays, means operated by such second relay for closing such shunt circu t, means for successively energizing the remaining relays of such series each from the one preceding it, means for maintainin suchrelays energized until the operation of the last of such relays, means operated by the last of such relays for disconnecting such conductors from such charging source and for connecting such conductors to such instrument and for at the same time deiinergizing one of such series of relays, means actuated by the detinergization of such last mentioned relay for deenergizing another of the relays of such series, .means for similarly delinergizing the remaining relays of such series, means actuated by the deenergization of the last relays of such series for disconnecting such conductors from such instrument and for immediately thereafter opening such shunt circuit whereby the apparatus is restored to its normal condition, such deenergizat-ion of such relays resulting from closing an external path of low resistance between the, terminals of one of such relays whereby the discharging interval through such measuring instrument is relatively greater than the charging interval of such conductors.

15. in a system for measuring the capacity of associated electrical conductors, a series of relays a. source' of electric cnergy adapted to operate such relays, a key for operating a first, relay-0f such series, a source oi electric energy adapt-ed'to charge the mud lu'tors to be tested, an instrument adapted to measure electrical capacity, a shunt. circuit of adjustable resistance adapted to be closed between the terminals of such instrument, means operated by such first relay for connecting the conductors to be tested to such charging source and for energizing a second of such relays, means operated by such second relay for closing'such shunt circuit, mcans foa' successively encrgizing thc remaining relays of such series each from the one preceding it, means for maintaining such relays energized until the operation of the last of such relays, means operated by the last of such relays for disconnecting such conductors from such charging source and for connecting such conductors to suchinstrument and forat the same. time deenergizing one of such series of relays, means actuated by the deenergization of such last mentioned relay for denergizing an: other of the relays of such series, means for similarly deenergizing' the remaining --relays of such series, means actuated by the deenergization of the last relays, of such series fordisconnecting such condurltors from such instrument and for immediiitlely thereafter ,opemng such shunt circuit whereby the apparatus is restored toits normal COIXdItlQXI,

such dei nergization of suehrelays resulting from closing external ancebetween' ,the terminals of such relays whereby the discharging interval through such measuring instrument, is relatively greater than the charging interval of such conductors.

16; In a system for measuring the capac-. ity of associated electrical'conductors, a series. 0t relays a, source-of electric energy adapted to operate such relays, a key for operating a first relay of such series, a source of electric energy adapted to charge the conductors to be tested, an instrument adapted to measure electrical capacity, a shunt circuit of adjustable resistance adapted to be closed between the terminals of such instrument, charging leads normally disconnected from such charging source and normally connected to the conductors to be tested and adapted to be connected tosuch charging source and disc0nnectcd....from such conductors, means operated'l'iy such first relay for connecting such charging leads to such charging source and for energizing a second of such relays, means operated by such second relay for closing such shunt circuit, means for successively energizing the remaining relays of such series each from the one preceding it, means for maintaining such relays energized until the operation of the last of such relays, means operated by the last of such relays tor disconnecting such conductors from such charging leads and for connecting such conductors to such instrument and for at the same time de energizing one (it such series of relays, means actuated by the deenergization of such last mentioned relay for disconnecting such charging loads from such chargingsource and for deii-uergizing anotherof the relays of such series, means for similarly decncrgizing the remaining relays of such series, means actuated by the deenergization of the last relays oF such series for disconnccting such conductors from such instrument and for immediately thereafter opening. such shuntecircuit. whereby-the apparatus is restored to its normal condition.

17. in a system formcasuring the capacity o associated electrical conductors, a. series of relays a source of electric energy adapted to operate inch relays, a key for opaths 'of low resisteratinga first irelay of such series, asource-of electric energy adapted to charge the con-l ductors to be tested, an instrument adapted to measure electrical capacity, a shunt cir cuitof adjustable resistance adapted to be closed between the terminals of such instrument, charging leads normally disconnected from such charging source and normally connected to the conductors to be tested and adapted to be connected'to such charging source and disconnected from such conductors, means operated bysuch first relay for connecting such charging leads to such charging source and for energizing a second of such relays, means operated by such second .relay for closing such shunt circuit, means for successively energizing the remaining relays'ot such series each from the one precedinglit, means for maintaining such relays energized until the operation of the last of-such relays, means operated by the last of such relays for disconnecting such conductors from such charging leads and for connecting such conductors to such instrument and for at the same time de energizing one of such series of relays, means actuated by the deenergization of i such last mentioned relay for disconnecting such charging leads from such charging source and for deenergizing another of the relays of such series, means for similarly decnergizing the remaining relays of such series, means actuated by the detincrgization of the last relays of such series for disconnecting suchconductors from such instrument and for immediately thereafter opening such shunt circuit whereby the apparatus is restored to its normal condition, such deenergization of such relays resulting from closing an external path of low resistance between the terminals of one of such relays whereby the discharging interval through such measuring instrument is relatively greater than the charging interval ot such conductors.

18. In a system for measuring the ca- "pacity of associated electrical conductors, a

series of relays a source of electric energy adapted to operate such'relzys, a key for operating a first relay of such series,asource of electric energy adapted to charge the conductors to be tested, an instrument adapted to measure electrical capacity, a shunt circuit of adjustable resistance adapted to be closed between the terminals of such instrument, charging leads normally disconnected from such charging source and normally connected to the conductors to be tested and adapted to be connected to such charging source and disconnected from such conductors, means operated by such first relay for connecting such charging leads to such charging source and for energizing asecond of such relays, means operated by such second relay for closing such shunt circuit,

means for successively energizing the .remaining relays of such series each fromthe one preceding it, means for maintaining such relays energized until the operation of the lastof such relays, means operated by the last of,such relays for disconnectingsuch conductors from such charging leads and for connecting such conductors to such instrument and for at the same time de energizing one of such series of relays, means actuated by the deenergization of such last mentioned relay for disconnecting such charging leads from suchcharging source and for deenergiz'ing another of the relays of such series, means for similarly deenergizing the remaining relays of such series. means actuated by the deenergiz'ailOllOf the last relays of such series for disconnecting such conductors from such instrument and for immediately thereafter opening suchshunt circuit whereby the apparatus is restored to its normal condition, such (leenergization of such relays resulting from closing external paths of low resistance between the terminals of such relays Whereby the discharging interval through such measuring instrument is relatively greater than the charging interval of such con-l ductors 19. In a system for measuring the capacity of associated electrical conductors, a capacity measuring instrument, a source of electric energy, a manually operated key, means controlled by the initial operation of said key for automatically connecting the conductors to said source for an unvarying period of. time and means also controlled by the initial operation of said key for disconnecting said conductors from said source and connecting them to the capacity measuring instrument. I

20. In a system for measuring the capacity of associated electrical conductors, a source of electricity, an instriunentfor measuring capacity, means adapted to be manually operated and means for automatically connecting the conductors to said source for an unyarying period of time and means for disconnecting them therefrom and connecting them to said instrument, the operation of the latter two means depending upon the initial operation of the manually operated means.

21. In a system for measuring the capacity of associated electrical conductors, a

22. In a system for measuring the capacity of associated electrical conductors, a the conductors from said source and then source of electric energy, an instrument for connecting them to said instrument for a 10 measuring capacity, a controlling switch,- predetermined interval. means controlled thereby for automatically OSCAR M. LEIGH. connecting the conductors to the said source CHARLES E. HAGUE.

for a predetermined, unva'rying interval, Witnesses: v and means controlled by thesame movement ARTHU R. KAHL of said controlling switch for disconnecting MONTGOMERY S. AN VLEE'L' 

